Process of treating shale



Apr. 10, 1923. 1,451557 S. MARKO PROCESS OF TREATING SHALE Filed Oct. 16, 1921 Patented pr. re, 1923.

FFICE;

PATENT STEPHAN MAB-KO, OF CHICAGO, ILLINOIS.

raoosss or rnm'rme SEALE. 4

Application filed October 10, 1921. Serial No. 506,757.

To all whom itma/y concern:

Be it known that I, S'rnPHArI MARKO, a citizen of the United States, residing at Chica 0, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Processes of Treating Shale, of which the following is a specification. i

My invention pertains to the production of combustible or illuminating gas by the treatment of the shale subjecting the expelled gas to the action of superheated steam,

thereby-rendering possible the production of the required gas in an inexpensive and 'efiective. way. o the attainment of these and other de-' sirable purposes, I have invented a novel and valuable process or method based upon the principle indicated above, whereby the combustible gas. may be produced both cheaply and by the-employment of-simple apparatus comparatively easily operated.

In order that those skilled in this art may have a full and.complete=understanding of a' suitableapparatus by which "this method or processinay'be racticed, in the accompanying drawin'g orming a part "of. this specification .I have illustrated such a structure, a thisdrawing' like reference charactors been appliedto the sameparts throu o e severalviewsu' nt aw i gm: w

--sectional" illustrating a suitable apparatus vforthe'.- 1 .p1'a"ctice of the process;

. Eigure2f'is'a vertical cross-sectionz on line fa-feast Figure 1; and

'FiguregB 1s a section illustrating one of I its shaft, coasting wlth a sprocket chain 25,

the rotary valves Re erririg to this drawing for an under-- standingof such an appropriate apparatus whicli'niay be conveniently employed for the; ca'rryi'l'i" of the process, it will be obtwo 2'! and 28,-t'hrough which the hot, exhaust, dry, combustion gases from acoal orserved't at this includes a first, inclined,

stationary, cylindrical-"retort or. casing 10' heat insulated by any suitable material, but

this feature of construction has not been shown since it is well understood in the art.

At its top near its upper end such retort is provided with a feed hopper ll equipped with a rotary valve 12 of ordinary type by means of which charges of the ground oilbearing shale are fed intermittently to the retort without an escape of gas therefrom.

This valve is shown more in detail in Figure 3 and comprises merely a round valve member 13 revoluble in an enclosing shell 14 having top and bottom openings or ports communicating respectively with the lower part of the hopper and the top'of the retort.

Such member or element 13 is so formed or shaped that, during'its rotation, while it is receiving acharge from the hopper, it

closes the passa e into the retort, and, conversely, when, uring its rotary movement, it delivers its charge into the retort, it closes the passage or port into the hopper, thus at all times eifectively preventing the escape I of gas from the retort or shell.

Such cylindrical retort has a central or axial longitudinal shaft 15 extended therethrough, being revoluble in external bear-i 'in'gs'16 and 17 the shaft inside of the retort having'a plurality of agitator or feeder arms or stirrers 18, 18 each of general open skeleton form, curved tsomewhat forwardly from the shaft, and- "'twisted or canted slightly, whereby to produce an efiicient,

stirring, lifting and forward feeding action on the ground shale preferably of about one-quarter inch in size. To this end, also, these arms or agitators are arranged spirally orin angularly stepped relationv around the {axis of the shaft whereby to act in series relation on-the material contained in the retort the latter beingabout half filled with o -such -round shale.

Shaft 15 is ,rotated' at-the proper speed from a main drive shaft '19,. revolved by an electric motor2Q or otherwise, by means of appropriate sprocket wheels 21 and 22 and an associated sprocket chain 23, and the valve 12 is rotated at the required speed by means ,of an external sprocket wheel 24 .on

cooperating with another sprocket wheel 26 von shaft 15, all as is clearlyillustrated.

Q11 0? P P PfWl hernias furnace are intro duced into the retort to heat the shale contained therein to a temperature of approximately 500 degrees Fahrenheit, any specific portion of the. ground shaleremaining in such retort and being subjected to the specified heat'for a period of an hour, more or less. i

The lower end of such inclined retort or casing is connected to the top or upper end of another similar sloping, heat-insulated retort 29 by means of a vertical pipe or connection 30 which may or may not contain a rotary valve 31 like the valve 12, rotated from shaft 15 by sprocket wheels 32 and 33 and a companion sprocket chain 3 L, all as will be readily understood from the illustration.

The shale continuously traversing the first retort by reason of the inclination of the latter and the feeding action of the revolving elements 18, when it reaches the lower end of such retort is delivered through pipe 30' into the second retort where it is subjected to the action of further heat and to the action of superheated steam.

Such second or lower cylindrical retort or chamber of suitable dimensions is similarly equipped with a centrallengthwise shaft 35, revoluble in external bearings 36 and 37 and inside the retort it is equipped with agitators, stirrers, paddles, or feeders 38 like those in the complementary retort, whereby the shale is thoroughly stirred and slowly fed forwardly.

The lower half only of retort 29 is externally heated by a plurality of electrical heatving units 39 which unitedly and conjointly encase or enclose the lower half of the cylin drical chamber or retort, such heating elements by any appropriate means being subject to regulation to govern and control their heat producing function and hence the temperature of the retort and its contents.

At its lower end retort 29 is fitted with a discharge pipe or chute l0 equipped with a rotary valve 41 like valve 12, which delivers the spent shale or shale residue into an underlying water chamber 42, the valve being rotated from shaft 35 by a suitable sprocket wheel and chain connection 43, as will be readily understood. 1 At the top of the lower end of such compartment 29 a pipe 44 delivers superheated steam at approximately two to three pounds I pressure into the retort to supply the necessary hydrogen to the gas which by the heat treatment of the oil shale has been driven oil or freed from the oil contained in the rock. i The temperature in such second or lower retort is maintained at temperatures in excess of 600 degrees Fahrenheit and the material treated occupies approximately one hour in traversing the chamber.

The illuminating or combustible gas de veloped or generated in retort 29, as Well as that which enters such retort from the upper one, is discharged or delivered therefrom through two valved pipes 45, 46 provided internally with bafiles or barriers 47 to remove dust and dirt from the gas, these pipes uniting in a single pipe 48 connected to a suction appliance, such as a fan 49, which causes the gas to pass through a condenser and scrubber into a gas holder or reservoir ready for consumption or combustion when needed, these latter members or pieces of apparatus being Well known in the art and hence not illustrated.

Another pipe 50 is connected to pipe or chute 40 by means of which through a suitable suction device not shown gas may be drawn off for use as fuel for the boiler which produces the superheated steam referred to, or it may be employed for any other suitable purposes.

Thus it will be seen that the reduced or sub-divided oil containing shale is first or preliminarily subjected to dry heat by the introduction of the hot gaseous products of combustion into the first retort and that in the second retort the shale is still further raised in temperature by the heat applied externally to the lower part only of such chamber, the expelled or freed gas derived from the oil content of the shale being charged with hydrogen from the superheated steam.

By thus effecting a substantial heating of the material in an economical manner without the use of steam in direct-contact therewith, the presence of an excess of moisture is avoided and the quantity of superheated steam used is substantially lessened.

The salient features of the invention lie in the heating of oil shale with dry combustion gases at temperatures sufiiciently high to separate incondensible gas therefrom. These temperatures will vary-according to the character of the shale which is treated. In the treatment of Colorado and Utah shale, temperatures from 600 to 900 degrees F. in the second retort are adequate to produce the gas desired. Kentucky shale necessitates temperatures from 1100 to 1300 degrees F., and Indiana shale, which is somewhat more of a slaty character, tempera tures in the neighborhood of 1300 degrees F. The shale having been treated by the dry combustion gas in the primary stage of heating during continual agitation by the paddles or mechanical agitators is passed to the secondary retort, which is externally heated by electrical heaters, shown'at 39.

oil constituents evolved in the second retort are separated after their removal therefrom into gas and oil distillates while certain byproducts contained in the liquors removed With the condensed water vapors are also separated. Although anintermittently op- :eratingvalve is shown between the retorts,

results indicate that the elimination of this valve give as satisfactory results, due to the fact that the vapors can pass more readlly where the retorts are in free communica ti'on, thus facilitating the reaction taking place in the separate stages.

Also, it is desirable to eliminate any '01)- struction between the two chambers in order that the vapor conditions in the two retort's may be maintainedrelatively constant. This secondary retort functions as the distilling chamber, the temperatures being increased relative to the temperatures in the initial.

stage, and controlled quantities of superheated steam added to supply the necessary hydrogen to the evolved gases. In the treat-- .ment of the shale a very limited quantity of steam is necessary to produce the desired efi'ect.

The process is one which lends itself to practicewith marked economy and to great commercial advantage for the reasons stated. 7 The invention is not limited and restricted to the precise and exact details specified because these may be modified within com-- paratively Wide limits Without departure from the heart and essence of the invention and without the sacrifice of any of its substantial benefits and advantages. .The pri-.

\ mary function of the process is to recover the gas,while the liquor and oil distillates occur only as 'by-p'roducts. Particular] reference has been made in this application to the production of a com-' bustible or illuminating gas, but it is'to be borne in mind that the gas generated in' passingthrough the condenser referred to is purified,resulting in the production not only of such gas. but also of crude oil and water vapor, from the latter of which sulphate of ammonia may be recovered.

claim: 1. A'process of producing combustible gas from oil-bearing shale, consisting in agitating ground shale in the presence of dry heated gaseous products of combustion at temperatures in excess of 600 degrees F., passing the heated shale and gases to a secondary zone of treatment and there continuously agitating the shale and subjecting it to increased temperatures and adding sufiicient quantities of superheatedsteam to the secondary stage of treatment to increase to a predetermined amount the hydrogen content of the evolved gases, separately withdrawing the gas and shale residue from the secondary stage of treatment. 7 2. A process of producing combustible gas .from oil-bearing shale, consisting in passing ground shale through successive closed retorts connected in series, agitating the shale in'the first retort and subjecting it to the treatment of heated, dry gaseous products of 

